CORE: Genetically Engineered Mouse Shared Resource (Cell and in vivo Biology Group) PROJECT SUMMARY The goal of the Genetically Engineered Mouse Shared Resource (GEM SR) is to assist Cancer Center Investigators with the design and execution of experiments to develop and utilize animal models for the investigation of the progression of cancer and preclinical evaluations of therapies for the treatment of cancer. The GEM SR facility began in 1987 as a Transgenic Mouse Core in the Center for Reproductive Research in the Department of Molecular and Cellular Biology. In 1996, it was adopted as an Institutional Core and changed its name to the Genetically Engineered Mouse Core with service restricted at that time to the generation of transgenic mice by microinjection of DNA into the pronucleus of the one-cell mouse embryo. As the field evolved, the GEM Core expanded its services to the most current production avenues for transgenic mouse models, as well as, the preservation and rederivation of transgenics for further use. The GEM facility is now a matrix Core co-managed and co-supported as an Institutional Advanced Technology Core (ATC) and as a Cancer Center Shared Resource. During the last funding period of the CCSG, the GEM SR incorporated improvements in sperm cryopreservation and in vitro fertilization and developed an efficient means of germline transmission of C57Bl/6N embryonic stem cells. Most recently for the current CCSG, we have initiated the new genome editing CRISPR/Cas approach. The GEM SR will continue to serve as a resource for the execution and training in the use of animal manipulations needed in the Cancer Center. This will minimize the cost of utilizing animal cancer models by consolidating the equipment, expertise, and animal resources required. The GEM SR will accomplish its goals by 1) generating transgenic mice of interest by traditional microinjection of DNA and/or RNA into the one-cell mouse embryo; 2) generating genetically engineered mice by targeting with genetically manipulated mouse embryonic stem cells; and 3) preserving transgenic mice through cryopreservation of mouse embryos and sperm.